1. Field of the Invention
The subject invention relates to printed circuit cards for add in I/O functions for computer systems. More particularly, the invention relates to an improved I/O connector for interfacing to external devices and networks through the RJ type connectors.
2. Description of the Prior Art
The PCMCIA (Personal Computer Memory Card International Association) standard was developed for the purpose of providing user installed memory and I/O functions for small form factor digital computer systems. The standard specifies a card containing a printed circuit board. This product is usually referred to as a PC card. There are three PC card formats: Types I, II and III. All three have external dimensions of 54 millimeters by 85.6 millimeters. Thicknesses vary. Type I is 3.3 millimeters thick. Type II is 5 millimeters thick. Type III is 10.5 millimeters thick. The standard specifies a 68 position socket on one end of the card. The 68 position socket mates with a 68 position plug mounted on a header which is in turn mounted to a mother board or daughter board which is located inside the host. There is a wide variation of headers in use including headers for different thickness cards; however, the 68 pin connector is common to all PCMCIA cards. The PCMCIA standard specifies the function of each of the 68 pins in the connector. The standard supports either an 8 bit or 16 bit bus. There are four ground pins, two power pins and up to 3 free signal pins for additional functions.
The original PC cards were intended to provide additional memory. No interaction with external devices was contemplated. Later, I/O cards were developed to add functions such as modems, facsimile, network interfaces, multi-media interface, sound cards, etc. In order to handle I/O functions, a second connector is located on the end of the card opposite the 68 position socket. The I/O connector reaches the outside world through a cable.
A communications card such as a modem or network interface must be connected to a network. The telephone network uses the RJ-11 modular jack for connecting individual telephones to the network and local area networks ("LAN") use RJ-45 modular jacks. The RJ-type jack is large compared to the card. It is thus difficult to attach to a card. To get around this problem, manufacturers have supplied custom adapter and cable assemblies. The adapter and cable assembly consists of a short cable with connector on both ends. One of the connectors was the plug of a RJ-type modular jack and the other connector was typically one end of a custom connector small enough to attach to the card. One problem with this approach is that the adaptor and cable assembly is often forgotten which makes the communication card useless. But, if the assembly is permanently attached to the card, it is frequently broken since their small size make them fragile. Thus, manufacturers have been seeking ways to provide an adaptor and cable assembly or its functional equivalent which is integral to the card and still robust.
One prior art approach to solving this problem is provided by U.S. Pat. No. 5,183,404, entitled SYSTEMS FOR CONNECTION OF PHYSICAL/ELECTRICAL MEDIA CONNECTORS TO COMPUTER COMMUNICATIONS CARDS and issued to Aldous et al which shows the use of a retractable RJ-type socket which stores within the body of the card when not in use.
A second problem with the communication card connectors is that the RJ-type jacks were not designed for frequent insertions and removals. The RJ-type jacks use a flexible locking mechanism to hold the plug into the socket. This design works well for stationary appliances such as telephones which require infrequent connections. But in today's mobile environment, the connect/disconnect action is frequent. And the locking mechanism on the RJ-type jack regularly breaks when subjected to regular connects and disconnects.
Yet another problem is the fact that the locking feature of the RJ-type jack means that it will not disconnect when subjected to a firm tug such as might happen when the user trips over the telephone wire. When this happens, the appliance to which it is attached is yanked off of a table onto the floor and sometimes broken or the RJ-type jack is broken rendering the appliance useless until the jack is replaced.